【单选题】Since about 1800, near the beginning of the industrial revolution, coal, petroleum and gas have been used at a rapidly increasing rate. The supply of these【B1】is limited and electric power is very【B2】...
【单选题】Since about 1800, near the beginning of the industrial revolution, coal, petroleum and gas have been used at a rapidly increasing rate. The supply of these【C1】______is limited and electric power is ve...